Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request
From: "Roy M. Silvernail" <cybrspc!roy@cs.umn.edu>
Newsgroups: comp.dcom.telecom
Subject: Reverse Modem Detection
Message-ID: <10730@accuvax.nwu.edu>
Date: 11 Aug 90 18:54:07 GMT
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X-Telecom-Digest: Volume 10, Issue 561, Message 9 of 10


dave%westmark@uunet.uu.net (Dave Levenson) writes:

> What in the world is "reverse modem detection"?  The originating modem
> remains silent, expecting answer-tone from the answering modem?  Does
> this box route silent callers to its modem port?  Or does it only work
> with some non-standard modems that make noise while awaiting answer?

A standard modem remains silent and waits for the answering modem to
send a carrier. However, most Hayes-compatible modems can be handed a
command such as 'ATDT5551234R', and they will dial, then go into
answer mode and _send_ a carrier. The box to which you refer
apparantly routes incoming carrier tone to the modem. This would work
fine for private use, but wouldn't be satisfactory for a BBS. (Too
hard to get users to use non-standard techniques.)

    Roy M. Silvernail   
    now available at:   
 cybrspc!roy@cs.umn.edu